The present invention relates to weft presenting devices for weaving looms, namely to those devices applied at one end of the looms with continuous weft feed, to feed the same with the weft threads which are then carried through the shed by the loom gripping and transport members (usually grippers).
As known, the conventional presenting devices normally comprise a plurality of presenting needles, through an end hole of which is let the weft thread to be fed and which are positioned parallel and oscillating partially inside a containment case, from which they project one at a time to present their own thread to the gripping and transport member, each with a movement selected by an electromagnet with movable core, which is in turn energized by the selection devices forming the pattern of the fabric being woven on the loom.
With the increase in the speed of looms, some difficulty has been found in obtaining from the conventional presenting devices the desired working reliability, indispensible for a correct and appropriate weaving, owing to the inertias and consequent imprecisions in the selection of the presenting needles operated by the electromagnets.
It has therefore been thought to modify the way of controlling the needles in the presenting devices, by combining the mechanical operation of such needles with an electromagnetic memory of their mechanical selection. The electromagnetic selection movement is thereby eliminated, thus considerably improving the performances of the presenting devices, wherein the needles selection speed is independent from the response times of the electromagnets.